U.S. patent number 4,817,827 [Application Number 07/178,348] was granted by the patent office on 1989-04-04 for ice dispenser.
This patent grant is currently assigned to Hoshizaki Electric Co., Ltd.. Invention is credited to Toshihiko Ishikawa, Yoshikazu Kito, Susumu Tatematsu.
United States Patent |
4,817,827 |
Kito , et al. |
April 4, 1989 |
Ice dispenser
Abstract
An ice dispensing apparatus includes an ice dispensing lever
which causes an ice dispensing signal to be produced when pressed,
whereby an ice dispensing auger is driven for a period during which
the ice dispensing signal is produced under the action of a relay
(X.sub.5). In response to the ice dispensing signal, a motor for
driving an agitator installed within an ice storage chamber is
driven for a first period (t.sub.1) and then stopped. The rest
state of the agitator driving motor is maintained until an
integrated value resulting from integration of periods during which
the ice dispensing signal is generated has attained the length of a
second period (t.sub.2). After the lapse of the second period
(t.sub.2), the agitator can be driven in response to subsequent
generation of the ice dispensing signal.
Inventors: |
Kito; Yoshikazu (Toyoake,
JP), Ishikawa; Toshihiko (Toyoake, JP),
Tatematsu; Susumu (Toyoake, JP) |
Assignee: |
Hoshizaki Electric Co., Ltd.
(Toyoake, JP)
|
Family
ID: |
13955342 |
Appl.
No.: |
07/178,348 |
Filed: |
April 6, 1988 |
Foreign Application Priority Data
|
|
|
|
|
Apr 13, 1987 [JP] |
|
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62-88881 |
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Current U.S.
Class: |
222/238; 62/344;
366/186 |
Current CPC
Class: |
F25C
5/24 (20180101) |
Current International
Class: |
F25C
5/00 (20060101); B01F 015/02 (); F25C 015/08 () |
Field of
Search: |
;62/305,344
;366/131,151,186,295,344 ;222/238,240,241,644,146.6 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kashnikow; Andres
Assistant Examiner: Weldon; Kevin P.
Attorney, Agent or Firm: Wenderoth, Lind & Ponack
Claims
What we claim is:
1. An ice dispenser apparatus including an ice storage chamber, an
ice dispensing mechanism mounted for rotation within said ice
storage chamber to dispense outwardly ice pellets stored within
said ice storage chamber, means operatively connected to said ice
dispensing mechanism for generating an ice dispensing signal to
trigger operation of said ice dispensing mechanism, agitator means
mounted for rotation within said ice storage chamber for agitating
the ice pellets within said ice storage chamber, and drive means
coupled to said agitator means for driving said agitator means,
said drive means being operatively coupled to said ice dispensation
signal generating means and adapted to be energized in response to
said ice dispensing signal, the improvement comprising:
first means (X.sub.5) operatively coupled to said ice dispensation
signal generating means and said ice dispensing mechanism for
causing said ice dispensing mechanism to be operated over a period
during which said ice dispensing signal is issued; and
second means (X.sub.4, X.sub.8, X.sub.9, TM.sub.1, TM.sub.2,
TM.sub.3) operatively coupled to said ice dispensation signal
generating means and said drive means for energizing said drive
means for a first period (t.sub.1) in response to generation of
said ice dispensing signal and for deenergizing said drive means
for a second period (t.sub.2) until the integrated value of the
periods during which said ice dispensing signal is issued has
attained the length of a second period (t.sub.2).
2. An ice dispenser apparatus as set forth in claim 1, wherein said
second means includes means for resetting the operation for
deenergizing said drive means unless said integrated value of the
period during which the ice dispensing signal is genrated attains
the length of said second period (t.sub.2) within a third period
(t.sub.3) which is set sufficiently longer than said second
period.
3. An ice dispenser apparatus as set forth in claim 1, wherein said
second means is operative to repeat a cycle including operation for
energizing said drive means over said first period and operation
for deenergizing said drive means over said second period when the
period during which said ice dispensing signal is issued exceeds a
sum of said first and second periods.
4. An ice dispenser apparatus as set forth in claim 2, wherein said
second means includes first and second time adjusting means capable
of adjusting the durations of said first and second periods,
respectively.
5. An ice dispenser apparatus as set forth in claim 4, wherein said
second means includes third time adjusting means capable of
adjusting the duration of said third period.
6. An ice dispenser apparatus as set forth in claim 1, further
including an ice dispensing switch, and a change-over switch
connected in series to said ice dispensing switch for changing over
the ice dispensing operation mode of said ice dispenser to either a
continuous dispensing mode or a constant amount dispensing mode,
wherein said change-over switch includes a continuous dispensing
mode enabling contact for enabling said continuous dispensing mode
by outputting the contact signal produced by said ice dispensing
switch intact as the ice dispensing enable signal and a constant
amount dispensing mode enabling contact connected in series to a
constant amount dispensing timer (TM.sub.7) for producing an ice
dispensing enable signal (ON signal) for a predetermined period
(t.sub.7) starting from the time point at which said ice dispensing
switch is closed.
7. An ice dispenser apparatus as set forth in claim 1, further
including a stored ice sensor disposed within said ice storage
chamber, and a long duration timer (TM.sub.6) capable of counting a
predetermined long period (t.sub.6A) when said stored ice sensor
produces a signal indicating the ice-filled state of said ice
storage chamber fully filled with the ice over a period exceeding
said predetermined long period, wherin said long duration timer
(T.sub.6) causes said second means to output the signal for driving
said drive means for a predetermined short time (t.sub.6B) when
said long duration timer (T.sub.6) has counted up to said
predetermined long period (t.sub.6A).
8. An ice dispenser apparatus as set forth in claim 7, wherein said
second means produces the driving signal for driving said drive
means over said predetermined short period until stopping the ice
making operation is stopped in response to the signal produced by
said stored ice sensor indicating said ice-filled state of said ice
storage chamber.
Description
CROSS-REFERENCE TO RELATED APPLICATION
Reference is hereby made to the following copending U.S. patent
application concerning related subject matter and assigned to the
assignee of the present invention:
"Ice Dispenser" by Yoshikazu Kito et al, assigned U.S. Ser. No.
127,500 and filed Dec. 1, 1987.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to an ice dispenser
apparatus for discharging or dispensing an amount of ice from an
ice storage chamber in response to an ice dispensation request
signal and more particularly to an ice dispenser apparatus of such
a novel and improved structure in which pulverization of ice pieces
or pellets stored within the ice storage chamber due to agitation
thereof can be suppressed to a minimum to thereby prevent
occurrence of a so-called arching phenomenon in which ice pellets
are rigidly connected to one another through molten ice powder
resulting from the pulverized ice pellets.
2. Prior Art
Heretofore, there have been used a variety of ice dispensing
machines, a typical one of which is disclosed in U.S. Pat. No.
3,651,656 and which will be described below in respect to the
structure having relevance to the understanding of the present
invention by referring to FIGS. 6 and 7 of the accompanying
drawings in which FIG. 6 shows the known ice dispenser with
portions being broken away and FIG. 7 shows an electric circuit for
controlling operation of the ice dispenser.
Now referring to FIG. 6 together with FIG. 7, when an ice
dispensing switch 110 is closed as a result of accumulation of ice
pellets within an ice storage chamber 128 as produced by an ice
making mechanism of the structure known per se, a relay 100 is
electrically energized through a contact 112of an ice dispensing
timer 118 and an ice dispensation activating switch 114, whereby a
relay contact 116 is closed. Consequently, a relay 104 is
electrically energized through a contact 102 of a time delay relay,
whereupon contacts 105 and 106 are closed to positions for
activating a drive motor 146 which then rotates an ice dispensing
auger 140 and an agitator 160 by means of a chain 156 suspended on
and around sprockets 150, 152 and 170. Thus, the ice pellets within
the ice storage chamber are caused to be dispensed through a
discharge port 142. The drive motor 146 is energized so long as the
ice dispensing switch 110 is closed or for a period preset in the
ice dispensation timer.
In the ice dispenser disclosed in the U. S. Patent mentioned above,
since the ice dispensing auger 140 serving for dispensation of ice
and the agitator 160 for agitating the ice pellets stored within
the ice storage chamber are rotated so long as the drive motor 146
is activated, some of ice pellets are likely to be pulverized into
ice powder. when the pulverized ice enters gaps between the stored
ice pellets and undergo melting and re-icing, and arching
phenomenon occurs, whereupon the ice pellets are rigidly adhered to
one another in an arch-like fashion. Once the arching phenomenon
takes place, difficulty is encountered in satisfactorily
discharging or dispensing all the ice pellets from the ice storage
chamber regardless of rotation of the agitator, since these ice
pellets bonded together and located outside of the region
insusceptible to the action of the agitator can not be collapsed
into separate ice pellets, giving rise to a problem. Besides, the
arching phenomenon tends to disadvantageously increase motor torque
required for rotating the agitator. Furthermore, the dispensed ice
pellets tend to assume non-uniformity in respect to the size and
shape, involving degradation in the quality of ice product possibly
down to waste ice chips.
SUMMARY OF THE INVENTION
It is therefore a principal object of the present invention to
provide an ice dispenser apparatus of such a structure in which
tendency of ice pellets stored in an ice storage chamber being
pulverized due to agitation thereof can be suppressed to a minimum
preventing the occurrnce of the arching phenomenon within the ice
storage chamber.
In view of the above object, an ice dispenser apparatus is provided
according to the present invention in which one or more agitators
for agitating ice pellets and an ice dispensing mechanism both
installed within an ice storage chamber are driven in response to
an ice dispensation request signal generated upon actuation of ice
dispensing means to dispense ice pellets stored in the ice storage
chamber, characterized by first means for causing the ice
dispensing mechanism to operate over a period during which the ice
dispensation signal makes appearance, and second means for driving
the agitator for a first period in response to the generation of
the ice dispensation request signal and subsequently inhibiting
operation of the agitator until an integrated value of the periods
during each of which the ice dispensation request signal is
produced has attained a second period.
In the operation of the ice dispenser apparatus, the agitator means
is driven for the first period of a relatively short duration (e.g.
of 0.5 to 1 second), which agitator means is then stopped upon the
lapse of the first period and subsequently caused to remain in the
rest state until the integrated value of the ice dispensing signal
durations becomes equal to that of the second period (e.g. of 10 to
20 seconds). By intermittently operating the agitator means in this
manner, undesirable production of ice powder (i.e. pulverized ice)
can be suppressed very significantly when compared with the prior
art ice dispenser in which the agitator is continuously driven
throughout the ice dispensing operation. In other words, the period
during which the agitator is driven is set to a duration short but
long enough to prevent the arching phenomenon from occurrence.
Accordingly, the ice pellets can be protected against the agitating
action of a long duration, whereby generation of the ice powder is
decreased correspondingly. In this manner, occurrence of the
arching phenomenon due to pulverization of ice, if any, can be
limited only to the region surrounding the outer periphery of the
rotating agitator, whereby the ice pellets bonded together can be
again easily collapsed under the action of the agitator. In other
words, with the rotation of the agitator over only a small angular
distance (of about 30.degree. to 60.degree. in terms of angle of
rotation), the ice pellets can be maintained in the substantially
loose state to be easily fed into the dispensing auger.
BRIEF DESCRIPTION OF THE DRAWINGS
In the course of the following detailed description, reference will
be made to the attached drawings in which:
FIG. 1 shows schematically in a side view a typical ice dispenser
apparatus to which the invention can be applied;
FIG. 2 is a vertical sectional view of the ice dispenser apparatus
shown in FIG. 1 taken along a line passing an ice storage chamber
provided in the apparatus;
FIG. 3 is a schematic diagram of a control circuit for controlling
operation of the ice dispenser apparatus shown in FIGS. 1 and 2 in
accordance with an exemplary embodiment of the invention;
FIG. 3A is a circuit diagram showing a circuit configuration of a
single-chip control circuitry incorporated in the control circuit
shown in FIG. 3;
FIGS. 4 and 5 show various timing charts for illustrating
operations of the circuits shown in FIGS. 3 and 3A;
FIG. 6 is a perspective view showing a main portion of a hitherto
known ice dispenser apparatus with parts being broken away; and
FIG. 7 is a diagram showing a control circuit arrangement for the
ice dispenser shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, referring to the drawings and more particularly to FIGS. 1 and
2, a reference numeral 1 denotes a cabinet or housing of an ice
dispenser constructed according to the present invention which is
generally of a box-like configuration and includes a machine
chamber 1a formed therein. Disposed fixedly within the machine
chamber 1a are an ice making mechanism 2 having a discharge port 3
and a water tank 4 containing water to be supplied to the ice
making mechanism 2. An ice storage chamber or stocker 5 made of a
heat insulation material is mounted adjacent to the discharge port
3 of the ice making mechanism 2. Mounted within the ice storage
chamber 5 at a top portion thereof is an ice storage level sensor 6
which servess to detect the state of the ice storage chamber 5
filled with ice pellets to the full capacity thereof and produces a
signal for stopping operation of the ice making mechanism 2.
Parenthetically, the ice making mechanism 2 may be implemented in
the form of a so-called auger type ice making machine whose
structure is well known in the art and thus omitted from detailed
illustration. It should however be mentioned that in the auger-type
100 making machine, water fed into a cylinder from the water tank 4
is cooled by a coolant flowing through a cooling pipe wound around
the outer periphery of the cylinder to thereby frozen to form an
ice layer on the inner wall of the cylinder. The ice layer is then
scraped off therefrom by means of a rotatable auger member driven
by an auger drive motor 2a. The flakes of ice resulting from the
scraping are compressed together to be reformed to columns of ice,
which are then pushed upwardly to the discharge port 3.
Disposed within the ice storage chamber 5 in a manner known
heretofore are agitators 7a and 7b for agitating the ice pellets
stored within the ice storage chamber, which agitators also may be
of known structure such as, for example, a rotatable shaft provided
with a helical blade and driven by respective agitator drive motors
8a and 8b shown in FIG. 2.
Further, an ice dispensing switch 12 is provided at a position
beneath the ice storage chamber 5 for producing an ice dspensation
request signal in response to actuation of an ice dispensing lever
11. More specifically, an ice dispensing auger member 9 is
rotatably mounted at the bottom of the ice storage chamber 5 and
adapted to perform the ice dispensing operation upon actuation of
the ice dispensing lever 11, while a motor 10 for driving the ice
dispensing auger in response to the signal produced by the ice
dispensing switch 12 is positioned externally of the ice storage
chamber 5.
FIG. 3 shows in a diagram a control circuit for controlling
operation of the ice dispenser according to an exemplary embodiment
of the invention. The control circuit is composed of a
refrigeration control circuitry 20a for controlling a refrigeration
system for the ice making mechanism 2 which includes a compressor,
a fan drive motor, a condenser, the auger drive motor 2a and
others, a water supply control circuitry 20b including a float
switch disposed within the water tank 4 and others, and a master
control circuitry 20c implemented on a single chip or substrate
which may also be constituted by a microcomputer or the like.
The compressor 21 which is a component of the refrigeration system
is connected in series to a normally open contact X.sub.2-1 of a
second relay X.sub.2 described in detail hereinafter, while the fan
motor 22 which also constitutes a part of the refrigeration system
is connected in parallel with the compressor 21, and the auger
drive motor 2a of the ice making mechanism 2 (FIG. 1) is connected
in series to a normally open contact X.sub.1-1 of a first relay
X.sub.1 described hereinafter and a protector 24. A seventh relay
X.sub.7 is connected in parallel with the serial connection of the
auger drive motor 2a and the above-mentioned normally open contact
X.sub.1-1. The motor 10 for driving the ice dispensing auger 9
constituting a main part of the ice dispensing mechanism is
connected in series with a normally open contact X.sub.5-1 of a
fifth relay X.sub.5. The agitator drive motors 8a and 8b for
driving the agitators 7a and 7b, respectively, are connected in
parallel with each other, wherein this parallel connection is
connected in series to a contact T.sub.1-2 of a first timer
TM.sub.1. The serial connection of the agitator drive motors 8a and
8b and the contact TM.sub.1-2 of the first timer TM.sub.1 is
connected in parallel with an eighth relay X.sub.8, wherein this
parallel connection is connected to a power supply source by way of
a normally open contact X.sub.4-1 of a fourth relay X.sub.4. A
parallel connection of a ninth relay X.sub. 9 and the first timer
TM.sub.1 is connected in series with a contact T.sub.2-1 of a
second timer TM.sub.2 and a contact T.sub.3-1 of a third timer
TM.sub.3 is connected in series with a contact T.sub.1-1 of the
first timer TM.sub.1, wherein both serial connections mentioned
above are connected to the power supply source through a parallel
connection of a normally open contact X.sub.8-1 of the eighth relay
X.sub.8 and a normally open contact X.sub.9-1 of the ninth relay
X.sub.9. The second timer TM.sub.2 is connected to a normally
closed contact X.sub.8-2 of the eighth relay X.sub.8 for
integrating the periods during each of which the normally closed
contact X.sub.8-2 is opened through energization of the eighth
relay X.sub.8. The purpose of the second timer TM.sub.2 is thus to
integrate the durations of the periods during each of which the ice
dispensing auger drive motor 10 is operated.
The water supply system control circuitry 20b and the master
control circuitry 20c are connected to the low voltage side of a
transformer 25 constituting a low voltage power supply source. In
the water supply system control circuitry 20b, the float switch 26
for controlling the water level within the water tank 4 is
connected in parallel with a normally open contact X.sub.3-1 of a
third relay X.sub.3, wherein this parallel connection is connected
in series to the third relay X.sub.3. Further, a solenoid of a
water supply valve 27 for supplying water to the water tank 4 is
connected in series with a normally closed contact X.sub.3-2 of the
third relay X.sub.3, and this serial connection is connected in
series to the low voltage power supply source (i.e. the low voltage
winding of the transformer 25).
The master control circuitry 20c has terminals tm.sub.1 and
tm.sub.2 connected to the low voltage power supply source by way of
a normally open contact X.sub.7-1 of the seventh relay X.sub.7, and
includes first, second, fourth and fifth relays X.sub.1, X.sub.2,
X.sub.4 and X.sub.5, respectively. Connected across the terminals
tm.sub.3 and tm.sub.4 of the master control circuitry 20c is a
serial connection of a normally open contact X.sub.3-3 of the third
relay X.sub.3 and a switch contact 6a of the ice storage level
sensor 6. Terminals tm.sub.5 and tm.sub.8 are connected to a
change-over switch 29, while terminals tm.sub.6 and tm.sub.7 are
connected to each other and to the ice dispensing switch 12. When
the change-over switch 29 is thrown to a contact 29a for
establishing a constant amount dispensing operation mode, the ice
dispensing auger 9 is controlled in the mode for dispensing ice
pellets in a predetermined constant amount. On the other hand, when
the change-over switch 29 is thrown to a contact 29b for
establishing a continuous ice dispensing mode, the ice dispensing
auger 9 is controlled in the mode for continuously dispensing ice
pellets.
The master control circuitry 20c may be constituted by a
microcomputer or realized in a conventional electric circuit
composed of discrete elements. An exemplary internal circuit
configuration of the master control circuitry 20c is shown in FIG.
3A in a block diagram. In this connection, it should be mentioned
that the circuit arrangement shown in FIG. 3A is merely to serve
for illustrating the internal function of the master control
circuitry 20c and thus may be replaced by any other means so far as
the equivalent function can be attained.
Referring to the block diagram shown in FIG. 3A, the master control
circuitry 20c includes a fourth timer TM.sub.4, a fifth timer
TM.sub.5, a sixth timer TM.sub.6 which may also be referred to as a
long duration timer, and a seventh timer TM.sub.7 which may also be
referred to as the constant amount dispensing timer. The timing
operations of these timers are illustrated in FIG. 4. Referring to
FIG. 4, the fourth timer TM.sub.4 responds to a closed circuit
signal appearing at the terminal tm.sub.3 to output a signal for
energizing the first relay X.sub.1 while it responds to
disappearance of the closed circuit signal at the terminal tm.sub.3
to interrupt the energization command signal to the first relay
X.sub.1 with a time lag t.sub.4 (which may be on the order of 150
seconds). The fifth timer TM.sub.5 responds to the closed circuit
signal appearing at the terminal tm.sub.3 to produce a signal for
energizing the second relay X.sub.2 with a time relay t.sub.5F
(e.g. of 60 seconds) while interrupting the energization command
signal to the second relay X.sub.2 in response to disappearance of
the above-mentioned closed circuit signal from the terminal
tm.sub.3 with a delay of time t.sub.5R (e.g. of 90 seconds). The
long duration timer or sixth timer TM.sub.6 is adapted to produce
an ON signal for a predetermined short period t.sub.6B (e.g. of 2
seconds) after having been held in the OFF state for a
predetermined long duration t.sub.6A (e.g. of two hours) and again
assume the OFF state for the long period t.sub.6A, which operation
is automatically repeated. When the output signal of the fifth
timer TM.sub.5 changes from the ON state to the OFF state, i.e.
when the energization command signal for the second relay X.sub.2
disappears, the ON signal mentioned above is instantly produced for
the predetermined short duration t.sub.6B, upon the lapse of which
the repetitive operation is automatically carried out. The seventh
timer TM.sub.7 also referred to as the constant amount dispensing
timer is so designed as to produce the ON signal for a
predetermined period t.sub.7 from the time point when the input
signal to the seventh timer TM.sub.7 changes from OFF to ON state
or level, as is illustrated in the timing chart shown in FIG.
5.
Now, operations of the ice dispenser apparatus and the control
circuit shown in FIGS. 1 to 4 will be explained by referring to
FIG. 5
When the power supply source (not shown) is turned on, the solenoid
of the water supply valve 27 is electrically energized by way of
the normally closed contact X.sub.3-2 of the third relay X.sub.3,
as a result of which the water supply valve 27 is opened to start
the water supply to the water tank 4. Upon attainment of a
predetermined water level within the water tank 4 and hence within
the icing cylinder of the ice making mechanism 2, the float switch
26 installed within the water tank 4 is closed, whereby the third
relay X.sub.3 is connected in series to the float switch 26 is
electrically energized to open the normally closed contact
X.sub.3-2 thereof, resulting in that the water supply valve 27 is
closed. Simultaneously with the opening of the normally closed
contact X.sub.3-2, the normally open contact X.sub.3-3 is closed,
whereby a closed circuit is established between the terminals
tm.sub.3 and tm.sub.4 of the master control circuitry 20c by way of
the contact 6a of the ice storage level sensor switch 6 when it is
closed at this time point. As a result, the electronic fourth and
fifth timers TM.sub.4 and TM.sub.5 of the master control circuitry
20c shown in FIG. 3A start the time count operation.
As described hereinbefore, since the fourth timer TM.sub.4 produces
the energization command signal for the first relay X.sub.1
instantly upon formation of the above-mentioned closed circuit, the
first relay X.sub.1 is energized at first to close the normally
open contact X.sub.1-1 thereof shown in FIG. 3, whereby the auger
drive motor 2a of the ice making mechanism 2 is driven. After the
lapse of the time t.sub.5F, the fifth timer TM.sub.5 produces the
energization command signal for the second relay X.sub.2, whereupon
the normally open contact X.sub.2-1 of that relay X.sub.2 is
closed. Consequently, the compressor 21 and the fan motor 22 are
driven to start the ice making cycle.
The ice pellets produced by the ice making mechanism 2 during the
ice making operation thereof are discharged through the ice
discharge port 3 into the ice storage chamber 5 to be progressively
accumulated therein. When the ice storage chamber 5 becomes full of
the ice pellets, the storage level sensor switch 6 is actuated to
open the contact 6a thereof. As a result, the closed circuit path
formed between the terminals tm.sub.3 and tm.sub.4 of the master
control circuitry 20c is opened. Upon the lapse of the time
t.sub.5R from this time point, the output signal of the fifth timer
TM.sub.5 is changed over from the ON state to the OFF state,
whereby the energization command signal for the second relay
X.sub.2 is interrupted to stop the operation of the compressor 21
and the fan motor 22, while the long duration timer, i.e. the sixth
timer TM.sub.6 produces the ON signal for the predetermined short
time t.sub.6B (e.g. of 2 seconds) upon detection of the ON-to-OFF
changing-over of the fifth timer TM.sub.5. The ON signal from the
sixth timer TM.sub.6 energizes the fourth relay X.sub.4 through an
OR circuit OR.sub.1 for the predetermined short period t.sub.6B,
whereby the normally open contact X.sub.4-1 of the fourth relay
X.sub.4 shown in FIG. 3 is closed.
In response to the closing of the normally open contact X.sub.4-1
of the fourth relay X.sub.4, the agitator drive motors 8a and 8b
are activated through the contact T.sub.1-2 of the first timer
TM.sub.1. At that time, the eighth relay X.sub.8 which is connected
in parallel with the motors 8a and 8b, as shown in FIG. 3, is also
energized. Upon energization of the eighth relay X.sub.8, the first
timer TM.sub.1 as well as the ninth relay X.sub.9 is electrically
energized through the normally open contact X.sub.8-1 of the relay
X.sub.8, the contact T.sub.2-1 of the second timer TM.sub.2 and the
contact T.sub.3-1 of the third timer TM.sub.3, whereby the ninth
relay X.sub.9 is held in the energized state (this state will be
referred to as the self-holding state) through the normally open
contact X.sub.9-1.
Upon energization of the first timer TM.sub.1, the timer contact
T.sub.1-1 is closed after lapse of a first period t.sub.1
(preferably a relatively short time, e.g. of 0.5 to 1 second
although it depends on the ice storage capacity and the structure),
while the timer contact T.sub.1-2 is opened to deenergize the
agitator drive motors 8a and 8b. In this way, the agitator drive
motors 8a and 8b are driven in response to the energization of the
fourth relay X.sub.4 only for the first period of the duration
t.sub.1 preset at the first timer TM.sub.1. Further, the closing of
the timer contact T.sub.1-1 brings about energization of the second
timer TM.sub.2 and third timer TM.sub.3 whose function will be
described hereinafter in conjunction with the ice dispensing
operation modes.
As will now be appreciated, the agitator drive motors 8a and 8b are
driven only for the first preset period t.sub.1 (e.g. of 0.5
second) after the lapse of the time t.sub.5R from the time point at
which the ice storage level sensor switch 6a was opened by
detecting the state of the ice storage chamber 5 filled with the
ice pellets, whereby a cone-like heap of the ice pellets as
accumulated is collapsed substantially flat. Subsequently, if the
ice storage level sensor switch 6a still remains in the opened
state, indicating the ice-filled state of the ice storage chamber
5, then the fourth timer TM.sub.4 interrupts the energization
command signal for the first relay X.sub.1 after the lapse of the
preset time t.sub.4 from the opening of the ice storage level
sensor switch 6a, resulting in that the normally open contact
X.sub.1-1 of the first relay X.sub.1 is opened to deenergize the
auger drive motor 2a, whereupon the ice making operation cycle
comes to an end.
When ice pellets are held within the storage chamber 5 without
being dispensed for a long period, there is a possibility that a
smooth dispensing operation might be hindered. For the purpose of
avoiding such undesirable situation, the agitators are periodically
driven. To this end, the long duration timer, i.e. the sixth timer
TM.sub.6 is so set that the ON signal is outputted for a preset
short period t.sub.6B (e.g. of 2 seconds) upon every lapse of a
predetermined long period t.sub.6A (e.g. of 2 hours), as is
illustrated in FIG. 4, to thereby energize the agitator drive
motors for the first preset period t.sub.1 (e.g. of 0.5 second) for
making even the heap of ice pellets.
The ice dispensing operation (i.e. operation for dispensing ice
pellets from the ice storage chamber 5) can be effected either in a
constant amount dispensing mode in which a predetermined constant
amount of ice is dispensed at a time or alternatively in a
continuous dispensing mode in which ice dispensing operation is
continued so long as the ice dispensing switch lever 11 is
actuated. The constant amount dispensing mode is realized by
throwing the change-over switch 29 shown in FIGS. 3 and 3A to the
constant amount dispensing mode contact 29a, while the continuous
dispensing mode is effectuated by throwing the change-over switch
29 to the continuous dispensing mode contact 29b.
FIG. 5 illustrates the timing operation in the constant amount
dispensing mode. In this mode, when the switch 12 is closed by
pushing the ice dispensing switch lever 11, the constant amount
dispensing timer or the seventh timer TM.sub.7 is turned on to
produce an ice dispencing signal for causing the fourth and fifth
relays X.sub.4 and X.sub.5 to be electrically energized, whereby
the respective normally open contacts X.sub.4-1 and X.sub.5-1 are
closed for a predetermined time t.sub.7 starting from the turn-on
of the seventh timer TM.sub.7. In response thereto, the drive
motors 8a and 8b for the agitators 7a and 7b which are connected in
series to the normally open contact X.sub.4-1 are energized to stir
the heap of ice pieces for facilitating the dispensing thereof,
while the drive motor 10 for the ice dispensing auger 9 connected
in series to the abovementioned normally open contact X.sub.5-1 is
also rotated for a predetermined time duration t.sub.7, whereby the
ice pieces or pellets are dispensed through the ice dispensing port
13 outwardly from the ice storage chamber 5. In this manner, the
dispensing operation continued for the predetermined time t.sub.7
results in dispensation of a corresponding amount of ice from the
storage chamber 5.
In this case, the period for which the ice dispensing auger drive
motor 10 is energized is equal to the aforementioned predetermined
time t.sub.7 for which the constant amount dispensing timer
TM.sub.7 continues to produce the energization command signal.
However, it should be noted that the time for which the agitator
drive motors 8a and 8b are energized is limited to the duration
t.sub.1 (preferably 0.5 to 1 second, by way of example) set at the
first timer TM.sub.1, as described hereinbefore in conjunction with
FIG. 4 and also can be seen in FIG. 5. More specifically, when the
normally open contact X.sub.4-1 is closed to electrically energize
the agitator drive motors and the eighth relay X.sub.8 to thereby
energize the first timer TM.sub.1 and the ninth relay X.sub.9 by
way of the normally open contact X.sub.8-1 and the contacts
T.sub.3-1 and T.sub.2-1, the ninth relay X.sub.9 is held in the
energized state by the normally open contact X.sub.9-1 thereof.
Subsequently, after the lapse of the first time or period t.sub.1
set at the first timer TM.sub.1,the contact T.sub.1-1 is closed
with the contact T.sub.1-2 being opened. In this way, since the
contact T.sub.1-2 is opened upon the lapse of the first time or
period t.sub.1, the period during which the agitator drive motors
are energized is set to the period t.sub.1. The second timer
TM.sub.2 and the third timer TM.sub.3 are also energized
simultaneously upon closing of the contact T.sub.1-1. However, the
energization of the second timer TM.sub.2 and the third timer
TM.sub.3 is continued through the normally open contact X.sub.9-1
now closed, even after the normally open contact X.sub.4-1 and
hence the normally open contact X.sub.8-1 are opened. Thus, even
when the normally open contact X.sub.4-1 is subsequently closed,
the agitator drive motors can not be energized because the contact
T.sub.1-2 is in the opened state due to energization of the first
timer TM.sub.1. To allow the agitator drive motors to be driven,
the time set at either the second timer TM.sub.2 or the third timer
TM.sub.3 must elapse to open either the contact T.sub.2-1 or
T.sub.3-1 to hereby release the ninth relay X.sub.9 from the
self-holding state.
The second timer TM.sub.2 is connected to the normally closed
contact X.sub.8-2 of the eighth relay X.sub.8. This contact
X.sub.8-2 is opened for a period during which thenormally open
contact X.sub.4-1 is closed to energize theeighth relay X.sub.8
provided that the ice dispensation request signal is being
produced. the second timer TM.sub.2 integrates the time or period
during which the normally open contact X.sub.5-1 is opened. More
specifically, since the normally open contact X.sub.5-1 is closed
to energize the ice dispensing auger drive motor so long as the ice
dispensation request signal is produced, the second timer TM.sub.2
integrates the time or period during which the ice dispensing auger
drive motor is energized. In this connection, the second timer
TM.sub.2 is so designed that at the time point when the value of
the integrated period or duration has attained a value of a second
preset time t.sub.2 (e.g. of 10 seconds), the second timer TM.sub.2
is deenergized to open the contact T.sub.3-1.
On the other hand, the third timer TM.sub.3 is electrically
energized upon closing of the timer contact T.sub.1-1 and
deenergized after the lapse of a third time or period t.sub.3 (e.g.
20 of minutes) to open the contact T.sub.3-1. The function of this
third timer TM.sub.3 is to release the ninth relay X.sub.9 from the
self-holding state upon the lapse of the third time or period
t.sub.3, even if the value resulting from the time integration
effected by the second timer TM.sub.2 remains short of the second
period t.sub.2 nevertheless of the lapse of a longer time because
the normally open contact X.sub.4-1 is not closed with the normally
closed contact X.sub.8-2 remaining closed for a long time. Such a
situation may occur when the ice dispensing operation is not
performed for a long time.
Referring to FIG. 5 at (a), when the ice dispensing switch 12 is
first turned on (pulse P.sub.1), the seventh timer TM.sub.7
continues to output the ice dispensing signal for a time or
duration T.sub.7, as is shown in FIG. 5 at (b), whereby the ice
dispensing auger drive motor 10 is driven. However, the agitator
drive motor is driven only for the first period t.sub.1, as can be
seen in FIG. 5 at (f). Assuming now that the length of the second
period t.sub.2 finally attained through integration by the second
timer TM.sub.2 is given by:
the agitator drive motor 10 then remains in the deenergized state
when the ice dispensing switch 12 is operated at a second time
(pulse P.sub.2), as shown in FIG. 5 at (a), although the ice
dispensing drive motor 10 is energized. When the ice dispensing
switch 12 is operated at a third time (pulse P.sub.3), as shown in
FIG. 5 at (a), the time (t.sub.2) integrating operation of the
timer TM.sub.2 comes to an end. Accordingly, after the lapse of the
period t.sub.7 " during which the seventh timer TM.sub.7 continues
to produce the ice dispensing signal, the contact T.sub.2-1 is
instantaneously opened, as shown in FIG. 5 at (g), to thereby
release the ninth relay X.sub.9 from the self-holding state. As a
result, the first time TM.sub.1, the second timer TM.sub.2 and the
third timer TM.sub.3 are reset to the initial state. At this time
point, the contact X.sub.4-1 is opened, while the contact X.sub.8-1
is closed, resulting in that the ninth relay X.sub.9 is again set
to the self-holding state, whereby the agitator drive motor is
again energized for the first period t.sub.1, as will be seen in
FIG. 5 at (f). In the assumed operation illustrated in FIG. 5, the
ice dispensing switch subsequently remains unoperated. Accordingly,
the integrated value in the second timer TM.sub.2 remains
unincremented. At a time point when the third period t.sub.3 has
elapsed, the contact T.sub.3-1 of the third timer TM.sub.3 is
instantaneously opened, as will be seen in FIG. 5 at (h), whereby
the ninth relay X.sub.9 is released from the self-holding state.
Thus, the first timer TM.sub.1 , the second timer TM.sub. 2 and the
third timer TM.sub.3 are reset to the initial state.
In this manner, the agitators 7a and 7b are actuated only for the
duration and the number of times as required for ensuring the
smooth ice dispensing operation. More specifically, when the time
set at the seventh electronical timer TM.sub.7 is shorter than the
time set at the second timer TM.sub.2, the durations of repeated
operations of the timer TM.sub.7 (i.e. durations of the repetitive
ice dispensing operations) are integrated by the second timer
TM.sub.2, wherein the agitators 7a and 7b are rotated for the first
period t.sub.1 in respose to the ice dispensation request signal
when the total sum of the integrated durations has attained a
preset value. In case the amount of ice to be dispensed at a time
in the constant amount dispensing mode is large with the time
t.sub.7 longer than (t.sub.1 +t.sub.2) being set at the constant
amount dispensing timer TM.sub.7, the agitators 7a and 7b are
operated intermittently for the first time or duration t.sub.1 upon
every lapse of the period (t.sub.1 +t.sub.2). By setting the
durations t.sub.1 and t.sub.2 such that the relation between the
amount Q.sub.1 of ice which can be easily dispensed by rotating the
agitators for the duration t.sub.1 and the amount Q.sub.2 of ice
dispensed by the ice dispensing auger for the duration t.sub.2
satisfies the condition that 2/3Q.sub.1 <Q.sub.2 <Q.sub.1,
the agitators 7a and 7b are driven within the range in which the
amount of ice required for the ice dispensing auger 9 to transport
can be supplied. In any case, the control is performed such that
the ratio between the duration for which the agitators are driven
and the duration required for ice dispensation is maintained
constant, whereby pulverization of ice can be suppressed to a
minimum. Further, so long as the length of the second period as
integrated remains short of the third period which is set
sufficiently longer than the second period, the agitators are
allowed to be driven every time the ice dispensation request signal
is generated, presenting thus no problem in the ice dispensing
operation.
Next, description will be turned to the operation in the continuous
dispensing mode. In contrast to the constant amount dispensing mode
in which the ice dispensation request signal continues to be
generated for the predetermined duration t.sub.7 i response to the
actuation of the ice dispensing lever 11, the ice dispensation
request signal continues to be generated so long as the ice
dispensing lever 11 is pressed in the case of the continuous
dispensing mode. Except for this, the continuous dispensing mode is
identical with the constant amount dispensing mode. In the
continuous dispensing mode, the ice dispensing signal, i.e. the
signal for energizing the fourth relay X.sub.4 and the fifth relay
X.sub.5 is produced continuously so long as the ice dispensing
switch lever 11 is pressed, whereby the normally open contacts
X.sub.4-1 and X.sub.5-1 of these relays are closed to energize the
ice dispensing auger drive motor 10 as well as the agitator drive
motors 8a and 8b. However, the rotation of the agitator drive
motors 8a and 8b is limited to the time span or period t.sub.1 from
the time point when the ice dispensing lever 11 has been operated,
so that the agitator drive motors 8a and 8b remain in the
deenergized state regardless of the repeated actuation of the ice
dispensing switch lever 11, until the second period t.sub.2 has
been reached through integration by the second timer TM.sub.2 or
the third timer TM.sub.3 has counted up to the third period
t.sub.3. Further, when the ice dispensing switch lever 11 is
pressed continuously for a period longer than (t.sub.1 +t.sub.2),
the ice dispensing auger drive motor 10 continues to run for that
period. However, the agitator drive motors 8a and 8b are operated
intermittently only for the first timer period t.sub.1 upon every
lapse of the duration (t.sub.1 +t.sub.2), as described
hereinbefore.
In conjunction with the operation illustrated in FIGS. 4 and 5, it
is preferred that the first, second and third timers TM.sub.1,
TM.sub.2 and TM.sub.3 be provided with first, second and third time
adjusting means so that the first, second and third timer periods
t.sub.1, t.sub.2 and t.sub.3 can be adjusted in a variable
manner.
As will be appreciated from the foregoing description, the fifth
relay X.sub.5 constitutes a first means for activating the
operation of the ice dispensing mechanism and more specifically the
ice dispensing auger 9 over a period during which the ice
dispensation request signal is issued, while the fourth relay
X.sub.4, the eighth relay X.sub.8, the ninth relay X.sub.9, the
first timer TM.sub.1, the second timer TM.sub.2 and the third timer
TM.sub.3 cooperate together to constitute second means for
energizing the agitators for the first period t.sub.1 and
subsequently deenergizing the agitators for the second period
t.sub.2 in response to the ice dispensation request signal
generated only once.
It should be mentioned again that in the ice dispensing modes
described hereinbefore in conjunction with FIG. 5, the agitators 7a
and 7b are not rotated continuously over the whole ice dispensing
period during which the ice dispensing auger drive motor is
continuously energized but is rotated only during the possible
shortest period which is required for assuring the smooth and
satisfactory ice dispensing operation by virtue of such control
that the ratio of the period during which the agitators are rotated
to the period during which the ice dispensing auger drive motor is
driven is maintained constant. This is advantageous in that not
only the amount of pulverized ice possibly produced during the
rotation of the agitator can be suppressed to a minimum, but also
the ice powder as produced can be discharged out of the ice storage
chamber together with the ice pellets without being left within the
chamber, whereby the so-called arching phenomenon can be positively
prevented from occurring in the ice storage chamber.
Although the invention has been described as applied to the ice
dispenser in which a pair of agitators are employed, it should be
appreciated that the invention is never restricted to the number of
the agitators. The invention can be applied to the ice dispenser
equipped with one or three or more agitators for assuring the
improved ice dispensing operation while suppressing the occurrence
of the arching phenomenon.
Further, although description has been made in conjunction with the
illustrated embodiment to the effect that the second means
constituted by the first timer TM.sub.1, the second timer TM.sub.2,
the third timer TM.sub.3, the eighth relay X.sub.8, the ninth relay
X.sub.9, etc. for controlling the rotation of the agitator drive
motors 8a and 8b are incorporated in the refrigeration system
control circuitry 20a, it will be readily understood by those
skilled in the art that the second means may be implemented in the
master control circuitry 20c in the form of electronic timers and
relays, wherein the agitator drive motor is directly energized
through the normally open contact X.sub.4-1 of the fourth relay
X.sub.4. With this arrangement, the number of wiring steps can be
reduced, whereby the invention can be carried out economically.
As will be seen, the ice dispenser according to the present
invention which is so arranged as to inhibit the rotation of the
agitator(s) for a predetermined period independent of the ice
dispensing period in the ice dispensing modes and in which the
agitators are rotated only for the shortest time required to assure
the satisfactory ice dispensing operation upon every lapse of the
predetermined period can suppress the amount of pulverized ice as
produced to a minimum to thereby prevent the arching phenomenon
which otherwise would hinder the ice pellet dispensing
operation.
While a specific embodiment of the invention has been described in
detail, it will be appreciated by those skilled in the art that
various modifications and alternatives to those details could be
developed in light of the overall teachings of the disclosure
Accordingly, the particular arrangements disclosed are meant to be
illustrative only and not limiting as to the scope of the invention
which is to be given the full breadth of the appended claims and
all equivalents thereof.
* * * * *